Biological research or testing, such as phenotypic screening, frequently involves growing collected or prepared biological samples in an incubator to evaluate the growth characteristics of the biological sample or create sufficient biological material for further evaluation. Multi-well or microtiter plates are a standard tool used to simultaneously handle and grow a plurality of biological samples. The simultaneous growth provided by multi-well plates is particularly advantageous as the growth time necessary for biological samples to reach the requisite size for evaluation ranges from several hours to several days. With certain biological samples, the growth of the biological sample is measured by inserting the multi-well plate into a reader. The reader includes a radiation emitter that applies visible light, infrared energy or other electromagnetic radiation to the biological sample in each well and measures the resulting optical density, absorbance, fluorescence or luminescence of the biological sample to determine the size and other features of the biological sample.
The advantages provided by multiple sample wells are offset by the challenge of simultaneously or efficiently monitoring the growth of the plurality of biological samples. As most biological samples require similar growth environments, a single incubator can often simultaneously provide the appropriate growth environment for each well in a multi-well plate or a plurality of multi-well plates. However, a reader must evaluate each well individually as the biological samples may grow at different rates. Accordingly, presently available readers have moveable radiation emitters positioned on mechanical arms or assemblies that move the emitter across the face of the multi-well plate to align the emitter with each well and apply the appropriate electromagnetic radiation to each well individually. The moving and sequentially operated emitter provides precise measurement of the biological sample, but substantially slows the evaluation process as the moving emitter must be continually repositioned. Similarly, the moving components must be precisely calibrated to align the emitter with the wells, which can have a mouth smaller than twelve millimeters in diameter. As a result, readers for monitoring growth multi-well plates are often very expensive to purchase and maintain.
A similar drawback is that presently available readers require the multi-well plate to be removed from the incubator and inserted into a special slot or tray. The slot or tray positions the multi-well plate such that the wells are aligned with positions pre-programmed into the movable emitter. As a result, if the multi-well plate is misaligned with the programmed position the measurements could be inconclusive or erroneous. As the multi-well plate must be repeatedly removed from the incubator and inserted into the reader over the course of the growth time, the risk of error is compounded. In addition, as the growth time can span hours or days, the continual monitoring of the multi-well plate can become tedious further increasing the likelihood that the multi-well plate will be improperly inserted and positioned due to operator error.